Boas can take a long time to court before they actually breed, some females aren't receptive right away (or ever, even if they've bred before). It can take months. When you said the male is courting, what do you see him doing? What is the female doing?
I usually introduce the male and if they are staying apart or no courting is seen (usually late at night), I'll separate after about 3-5 days, then try reintroducing 2 weeks later, repeat, until I see actual courting.
There's not really anything *you* can do to entice them, besides some quite, darkness and Barry White music.
Edit to add - in all the boa litters I've had over the years, I've still never seen actual copulation, they don't 'lock up' like pythons do, they seem to prefer privacy.